Control of wind power plants

Abstract

Wind turbines power plant is a popular supplementary power plant in today energy

thriving world. Basically wind turbine power plant is a combination of devices that

convert wind energy (kinetic energy) to mechanical energy and then the later is used to

produce electricity. A reliable control system plays a critical role in order to produce

stable output voltage for grid under variable wind speed.

In this project, the doubly fed induction machine is used as a generator. The stator is

connected directly to the grid and the rotor is fed by a bidirectional converter that is also

connected to the grid. Using Vector Control (Field Oriented Control) technique, the

bidirectional converter assures energy generation at nominal grid frequency and

nominal grid voltage independently of the rotor speed. The converter’s main aim is to

compensate for the difference between the speed of the rotor and the synchronous

speed with the slip control. The advantage of DFIG over squirrel cage induction

generator (SCIG) and is having a smaller in size of bidirectional converter and nominal

power filter. Moreover DFIG is smaller than multi pole permanent magnet synchronous

generator (PMSG) due to without having the multi poles.